Surface area to volume ratio

Question 1

What size organism is more likely to have a higher SA:V

Answer 1

smaller organisms e.g. hippo vs mouse, mouse has a higher SA:V ratio

Question 2

What’s the relationship between SA:V and metabolic rate?

Answer 2

-Rate of heat loss increases as SA:V increases
-more heat lost in smaller organisms with high SA:V
-so they need a higher metabolic rate (faster respiration)
-small organisms with high SA:V have a high demand for oxygen and to remove carbon dioxide

Question 3

What are adaptations to facilitate exchange as this ratio reduces in larger organisms?

Answer 3

-larger organisms need a specialised surface/organ needed for gas exchange e.g. lungs
-because they have bc a smaller SA:V and long bc diffusion pathway (and bc skin is waterproof)
-as well as having high demand for ocean and to remove carbon dioxide

Question 4

What are the adaptations of gas exchange surfaces shown by gas exchange across the body surface of a single called organism?

Answer 4

-Thin flat shape
-Large SA(:V)
-Short diffusion pathway
-for rapid diffusion